JP2022054253A - Sheet conveyance device and image formation device - Google Patents

Abstract

To solve the problem that a work for detaching a gear is required before moving a conveying roller in an axial direction when the conveying roller supported by a frame is detached.SOLUTION: A sheet conveyance device comprises: a conveying roller for conveying a sheet; a frame for supporting the conveying roller; a gear for rotating integrally with a shaft of the conveying roller; and a gear support part for supporting the gear. The frame has a contact part with which a side end part of the gear is brought into contact. When the conveying roller is moved in an axial direction for detaching the conveying roller from the frame, the side end part of the gear is brought into contact with the contact part and movement of the gear in the axial direction is restricted, so that engagement of the shaft of the conveying roller and the gear is disconnected, and the gear is supported by the gear support part, and the gear is supported at a position where the shaft of the conveying roller can be inserted and attached, by the gear support part, when the conveying roller is attached to the frame.SELECTED DRAWING: Figure 4

Description

The present invention relates to a sheet transporting device for transporting sheets and an image forming apparatus including the same.

The electrophotographic image forming apparatus includes a sheet conveying device that conveys the sheet toward the image forming portion in order to form an image on the sheet. The sheet transfer device is provided with a transfer roller that abuts on the sheet and conveys the sheet.

In recent years, as the life of an image forming apparatus has been extended, the durability of a transport roller has been required. Various studies have been conducted on extending the life of the transport roller, but the transport roller may be replaced regularly in order to cope with the usage environment of the image forming apparatus and various sheets to be transported.

Patent Document 1 discloses a technique for removing a transport roller from a frame with respect to a transport roller provided with a gear on one end side of the shaft and supported by the frame.

Japanese Patent Application Laid-Open No. 11-227977

However, in Patent Document 1, when the transfer roller is removed from the frame that rotatably supports the transfer roller, after removing the gear provided at one end of the shaft of the transfer roller, the transfer roller is moved in the axial direction to the frame. Had to be removed from. That is, the operator had to remove the gear from the shaft of the transport roller before moving the transport roller in the axial direction. Therefore, an object of the present invention is to provide a sheet transfer device capable of removing the transfer roller from the frame while improving the workability of the operator in view of the above problems.

In order to solve the above problems, the sheet transfer device of the present invention has a transfer roller that transfers a sheet, a frame that rotatably supports the transfer roller, and a gear that rotates integrally with the shaft of the transfer roller. And a gear support portion provided on the frame to support the gear, the frame is provided with the gear when the transport roller is axially moved to remove the transport roller from the frame. It has a contact portion with which the side end portion contacts, and when the transport roller is moved in the axial direction in order to remove the transport roller from the frame, the side end portion of the gear comes into contact with the contact portion. By restricting the axial movement of the gear, the shaft of the transfer roller is disengaged from the gear, and the gear is supported by the gear support portion when the transfer roller is removed from the frame. The gear is characterized in that when the transfer roller is attached to the frame, the shaft of the transfer roller is insertable and is supported by the gear support portion at a position where the transfer roller can be attached.

According to the present invention, it is possible to provide a sheet transfer device capable of removing a transfer roller from a frame while improving workability when removing the transfer roller from the frame.

Sectional drawing of image forming apparatus in embodiment of this invention Perspective view of the double-sided transport unit according to the first embodiment Sectional drawing which shows the drive transmission part and the transfer roller of the double-sided transfer unit in 1st Embodiment Sectional drawing which shows the engagement between the transfer roller and a gear of a double-sided transfer unit in 1st Embodiment

[Embodiment 1]
Hereinafter, the image forming apparatus including the sheet transporting apparatus according to the present invention will be described with reference to the drawings together with the operation at the time of image forming. The dimensions, materials, shapes, relative arrangements, etc. of the components described below are not intended to limit the scope of the present invention to those, unless otherwise specified.

<Image forming device>
The first embodiment of the present invention will be described. The printer 1 as an image forming apparatus is an electrophotographic full-color laser beam printer. The printer 1 is connected to the discharge accessory 120 as a downstream device, and delivers the sheet to the inlet roller pair 121 provided in the discharge accessory 120.

As shown in FIG. 1, the printer 1 includes feeding units 10a and 10b, drawing units 20a and 20b, a registration unit 30, an image forming unit 90, a fixing unit 52, and a branch transfer unit 60. Have. Further, the printer 1 has a decaler unit 110, an inverting transfer unit 80 as an inverting transfer unit, and a double-sided transfer unit 70.

The image forming unit 90 includes four process cartridges 99Y, 99M, 99C, and 99Bk that form toner images of four colors of yellow (Y), magenta (M), cyan (C), and black (K), respectively, and an exposure apparatus. It is equipped with 93, 96, 97, 98 and so on. The four process cartridges 99Y, 99M, 99C, and 99Bk have the same configuration except that the colors of the formed images are different. Therefore, only the configuration of the process cartridge 99Y and the image forming process will be described, and the description of the process cartridges 99M, 99C, 99Bk will be omitted.

The process cartridge 99Y includes a photosensitive drum 91, a charging roller (not shown), a processor 92, and a cleaner 95. The photosensitive drum 91 is configured by applying an organic photoconducting layer to the outer periphery of an aluminum cylinder, and is rotated by a drive motor (not shown). Further, the image forming unit 90 is provided with an intermediate transfer belt 40 that is rotated in the arrow T direction by the drive roller 42, and the intermediate transfer belt 40 is wound around the tension roller 41, the drive roller 42, and the secondary transfer inner roller 43. Has been done. Primary transfer rollers 45Y, 45M, 45C, and 45Bk are provided inside the intermediate transfer belt 40, and on the outside of the intermediate transfer belt 40, the secondary transfer outer roller faces the secondary transfer inner roller 43. 44 is provided.

The fixing unit 52 has a fixing roller pair 54 and a pre-fixing guide 53 that guides the sheet to the nip of the fixing roller pair 54. The feeding unit 10a separates the lift plate 11a that moves up and down while loading the seat S, the pickup roller 12a that feeds the seat S loaded on the lift plate 11a, and the fed seat one by one. It has a roller pair 13a. Similarly, the feeding unit 10b includes a lift plate 11b that moves up and down while loading the seat S, a pickup roller 12b that feeds the seat S loaded on the lift plate 11b, and one fed sheet. It has a separation roller pair 13b for separation.

Next, the image forming operation of the printer 1 configured in this way will be described. When an image signal is input to the exposure apparatus 93 from a personal computer or the like (not shown), the laser beam corresponding to the image signal is emitted from the exposure apparatus 93 onto the photosensitive drum 91 of the process cartridge 99Y.

At this time, the surface of the photosensitive drum 91 is uniformly charged to a predetermined polarity and potential in advance by a charging roller, and the surface is electrostatically latent imaged by being irradiated with laser light from the exposure device 93 via the mirror 94. Is formed. The electrostatic latent image formed on the photosensitive drum 91 is developed by the developing device 92, and a yellow (Y) toner image is formed on the photosensitive drum 91.

Similarly, the photosensitive drums of the process cartridges 99M, 99C, and 99Bk are also irradiated with laser light from the exposure devices 96, 97, and 98, and the photosensitive drums are of magenta (M), cyan (C), and black (K). A toner image is formed. The toner images of each color formed on each photosensitive drum are transferred to the intermediate transfer belt 40 by the primary transfer rollers 45Y, 45M, 45C, and 45Bk. Then, the full-color toner image is conveyed to the secondary transfer nip T2 formed by the secondary transfer inner roller 43 and the secondary transfer outer roller 44 by the intermediate transfer belt 40 rotated by the drive roller 42. The toner remaining on the photosensitive drum 91 is recovered by the cleaner 95. The image forming process of each color is performed at the timing of superimposing the upstream toner image primaryly transferred on the intermediate transfer belt 40.

In parallel with this image forming process, the sheet S is fed from any of the feeding units 10a and 10b, and the sheet S is conveyed to the registration unit 30 by any of the drawing units 20a and 20b. The sheet S is skewed by the registration unit 30, and is conveyed to the secondary transfer nip T2 as an image forming portion at a predetermined transfer timing. A full-color toner image on the intermediate transfer belt 40 is transferred to the first sheet surface (surface) of the sheet S at the secondary transfer nip T2 by the secondary transfer bias applied to the secondary transfer outer roller 44. The residual toner remaining on the intermediate transfer belt 40 is recovered by the belt cleaner 46.

The sheet S on which the toner image is transferred is conveyed to the fixing unit 52 by the post-transfer guide 45 and the pre-fixing transfer unit 51. Then, the sheet S is guided to the nip of the fixing roller pair 54 by the pre-fixing guide 53, and predetermined heat and pressure are applied to melt and fix (fix) the toner. The sheet S that has passed through the fixing unit 52 is route-selected by the branch transfer unit 60 to be transported to the decaler unit 110 or the reverse transfer unit 80. The branch transfer unit 60 and the reverse transfer unit 80 invert the sheet S so that the first sheet surface on which the image is formed by the secondary transfer nip T2 is on the lower side, and transfer the sheet S to the decaler unit 110. You can also do it.

When an image is formed on only one side of the sheet S, the sheet S is transferred from the branch transfer unit 60 to the decaler unit 110, and the curl of the sheet is corrected by the small diameter hard roller and the large diameter soft roller. Subsequently, the sheet S that has passed through the decala unit 110 is conveyed to the discharge accessory 120. In the discharge accessory 120, after processing the sheet S, the sheet S is discharged to the discharge tray 130.

When an image is formed on both sides of the sheet S, the sheet S is conveyed to the reverse transfer unit 80 by the branch transfer unit 60 and switched back by the reverse transfer unit 80. The switched back sheet S is conveyed from the reverse transfer unit 80 to the double-sided transfer unit 70 and guided to the registration unit 30. After that, an image is formed on the second sheet surface (back surface) of the secondary transfer nip T2, and the sheet S is discharged to the discharge tray 130 via the decaler unit 110 and the discharge accessory 120.

<Double-sided transfer unit>
FIG. 2 is a perspective view showing the entire double-sided transfer unit 70, showing a state in which the double-sided transfer unit 70 is fixed to a slide rail (not shown) in the direction of arrow A and pulled out from the printer 1 toward the front side. The double-sided transfer unit 70 is composed of a double-sided upper frame 132, a double-sided front frame 133, a double-sided left frame 134, a double-sided rear frame 135, a double-sided right frame 136, and a grip portion 137. A transport drive roller 1260 (1270, 1280, 1290), which is a transport roller, is rotatably supported on the double-sided upper frame 132. The transport roller 1260 is composed of a rubber portion 1261 that abuts on the sheet and a metal shaft portion 1262 that rotates integrally with the rubber portion. The same applies to the transfer rollers 1270, 1280, and 1290. The rotary drive is transmitted to the transfer rollers 1260 and 1270 by the double-sided drive motor left 138 which is the first drive source, and the rotary drive is transmitted to the transfer drive rollers 1280 and 1290 by the double-sided drive motor right 139 which is the second drive source. Be transmitted. The transfer roller 1260 (1280) provided upstream in the sheet transfer direction, which is rotationally driven by the double-sided drive motor 138 (139), is an upstream transfer roller, and is a transfer roller 1270 (1290) provided downstream in the sheet transfer direction. Is a downstream transfer roller.

FIG. 3 shows a gear train that transmits drive from the left 138 of the double-sided drive motor to the transfer rollers 1260 and 1270. In the present embodiment, the description of the gear train for transmitting the drive from the double-sided drive motor right 139 to the transfer rollers 1280 and 1290 will be omitted because the configuration is the same as described above. FIG. 3A is a cross-sectional view of the entire drive transmission unit, FIG. 3B is a diagram showing engagement between the transfer roller 1260, the drive gear, and 140, and FIG. 3C is a transfer drive roller 1270. It is a figure which shows the engagement with a drive gear 142. In this embodiment, the drive gears 140 and 142 are the same parts.

The driving force from the double-sided drive motor left 138 is transmitted to the idler gear pulley 147 via the drive motor pulley 149 and the drive motor belt 148. Further, the idler pulley 147 is connected to the idler gears 143, 144, 145, 146 and is connected to the drive gear 142 provided at the end of the shaft of the transfer roller 1270. Further, the drive gear 142 is provided with a pulley portion 142b, which is connected at one end side of the drive connecting belt 141. The other end of the drive connecting belt 141 is connected to a drive gear 140 provided on the drive transfer roller 1260. This belt pulley mechanism enables drive transmission even when the transport rollers are arranged at positions separated in the seat transport direction.

As shown in FIG. 3B, the end portion of the shaft portion 1262 of the transport roller 1260 has an engaging portion 1262a having a D-shaped cross section. Similarly, the engagement hole 140c of the drive gear 140 is also formed in a D shape in cross section, and the rotational drive of the drive gear is communicably engaged with the shaft portion of the transport roller. As a result, the shaft of the drive transfer roller 1260 and the drive gear 140 can rotate integrally. Similarly, the drive transfer roller 1270 and the drive gear 142 are configured to rotate integrally. As described above, the driving force from the double-sided drive motor 138 is configured to transmit rotary drive to both the drive transfer roller 1270 and the drive transfer roller 1260 via gears and belts.

Next, fixing of the transport roller 1260 and the double-sided upper frame 132, which is a frame that supports the transport roller, will be described. Similar to the above, the transfer roller 1270 has the same configuration and is omitted. FIG. 4 shows a cross-sectional view of the transfer roller 1260 attached to the double-sided transfer unit 70 in the axial direction of the transfer roller 1260. 4A shows an overall cross-sectional view of the double-sided transfer unit 70, FIG. 4B shows an enlarged view of a mounting portion of the drive gear 140, and FIG. 4C shows a transfer roller shaft having a drive gear. The figure of the state which was removed from 140 is shown.

A bearing 1263, which is a bearing, is attached to the shaft portion 1262 of the drive transfer roller 1260 so as to penetrate both ends of the shaft. The bearing 1263 is attached so as to support the attachment portions 132c and 132d of the frame 132. That is, the inner diameter portion of the bearing rotates integrally with the shaft portion of the drive transport roller, and the outer diameter portion of the bearing is held so as to be fitted with the hole portion provided in the frame portion. As shown in FIG. 4B, the bearing is provided with a flange on one side in the axial direction, and the movement of the bearing to the right side is restricted in the drawing. Then, in order to regulate the axial movement of the drive transfer roller 1260 with respect to the frame 132, the E-ring 1264 was used as the regulating member in this embodiment. The E-rings are inside the bearings provided at both ends of the drive transfer roller 1260, and are attached to the E-ring mounting portions 1264b of the shaft, respectively, so as to restrict the axial movement of the rollers. That is, in FIG. 4B, when the shaft of the transport roller to which the E-ring is attached moves to the right side, the side surface of the E-ring comes into contact with the flange portion of the bearing, so that the movement of the shaft to the right side is restricted. Will be done. By configuring the same configuration on the other end side of the shaft, the movement of the shaft to the left side is restricted, and the axial position of the transport roller and the frame is determined.

On the other hand, two driven rollers 1265 are attached to the double-sided lower guide 131 so as to be in pressure contact with the rubber portion of the transport roller attached to the double-sided upper guide 132. The sheet conveyed by the double-sided transfer unit 70 passes through the guide surface 131a of the double-sided lower guide 131 and the guide surface 132a of the double-sided upper frame 132. The double-sided lower guide 131 is provided with a driven roller mounting portion 131b, and a driven bearing 1267 and a driven pressure spring 1268 are mounted on both ends of the driven roller shaft 1266 mounted through the mounting portion. It is urged to press contact with the rubber part of.

With the above configuration, the sheet transported to the double-sided transport path can be stably transported. The double-sided lower guide 131 is rotatably attached in the direction of arrow B around the hinge portion 132b of the double-sided upper frame 132. This makes it possible to remove the sheet jammed in the double-sided transport path.

<Removal of double-sided transport roller>
Next, the removal of the transport roller provided in the double-sided transport unit of the present embodiment from the frame will be described.

As described above, the drive gear 140 is attached to one end side of the shaft of the transport roller 1260 attached to the double-sided upper frame 132. Further, in the present embodiment, as shown in FIGS. 3 and 4, a gear support portion 156 having a holding portion 156a is provided so as to cover the lower side in the vertical direction of the drive gear. The holding portion 156a prevents the drive gear from falling when the drive gear 140 is removed from the shaft portion 1262 of the transport roller 1260. Further, the gear support portion 156 is fixed to the frame 132 on both sides by screws, and further, a rib 156b for restricting the movement of the gear in the axial direction is provided. As shown in FIG. 3, when the gear is attached to the shaft of the transport roller, it is attached so as to provide a gap between the outer peripheral portion of the gear and the holding portion 156a of the gear support portion. Similarly, the drive gear 142 attached to one end of the transport roller 1279 is also provided with a gear support portion 157.

Next, a procedure for removing the transport roller 1260 from the double-sided upper frame 132 will be described. First, in order to release the pressure contact state between the drive transfer roller and the driven roller, the double-sided lower guide 131 is rotated in the B direction shown in FIG. 4A. Next, in order to allow the transfer roller to move in the axial direction, the E-ring 1264 on the back side of the unit attached to the transfer roller shaft is removed from the upper part of the double-sided transfer unit 70. This makes it possible to move the transport roller with respect to the frame in the axial direction, particularly in the back side direction. By moving the transport roller to the back side, the operator disengages the gear from the D-cut portion of the transport roller shaft as shown in FIG. 4 (c). That is, when the conveyor shaft is moved to the back side, the shaft of the conveyor roller and the gear are not disengaged at the beginning of the movement, and the shaft and the gear are integrally moved in the axial direction. When the shaft is further moved, the side end portion 140d of the gear comes into contact with the end portion 132e which is the contact portion of the frame. When the shaft is further moved, the transport roller shaft moves relative to the gear. That is, the transport roller shaft and the gear are disengaged. The gear that is disengaged from the transport roller shaft and the gear falls downward in the vertical direction. However, the holding portion of the gear support portion described above makes it possible to hold the disengaged gear. Further, in the present embodiment, as shown in FIG. 4C, the region of the D-cut hole in the vertical direction of the disengaged gear and the region of the D-cut shaft of the transport roller in the vertical direction overlap each other. It is configured. As a result, when the transfer roller for new attachment is attached to the frame, the transfer roller shaft can be moved in the axial direction so that the transfer roller can be inserted into the hole of the gear, and the work by the operator can be facilitated.

With the above configuration, it is possible to remove the double-sided drive roller 1260 from the double-sided upper frame 132 by removing the regulating member from the transport roller and moving the transport roller in the axial direction without removing the drive gear 140 from the double-sided transport unit. Become. That is, by moving the transport roller in the axial direction, the gear is disengaged from the transport roller shaft, so that the work by the operator can be facilitated. Further, the surfaces 142a and 140a of the gear are often greased in consideration of durability and quietness, and the transport drive roller 1260 can be removed without touching the drive gear 140 by the above configuration. Further, when the transfer roller is attached to the frame after removal, the position of the hole of the drive gear held by the gear support portion 156 and the position of the axis of the transfer roller to be attached are configured to overlap with each other in the vertical direction. Is easy.

70 Double-sided transfer unit (sheet transfer device)
1260 (1270, 1280, 1290) Double-sided transfer drive roller (transfer roller)
1262 shaft 1263 bearing (bearing)
1264 E-ring (regulatory member)
132 Double-sided upper frame (frame)
132e Contact part 138 (139) Motor (drive transmission means)
140 (142) Drive gear (gear)
140b (142b) Pulley part (belt pulley means)
141 Belt (belt pulley means)
156 (157) Gear support

Claims (6)

A transport roller that transports the sheet and
A frame that rotatably supports the transport roller and
A gear that rotates integrally with the shaft of the transport roller,
A gear support portion provided on the frame and supporting the gear is provided.
The frame has a contact portion with which a side end portion of the gear comes into contact when the transport roller is moved axially to remove the transport roller from the frame.
When the transport roller is moved in the axial direction in order to remove the transport roller from the frame, the side end portion of the gear comes into contact with the contact portion and the axial movement of the gear is restricted. The shaft of the transport roller is disengaged from the gear,
The gear is supported by the gear support when the transport roller is removed from the frame.
The gear is supported by the gear support portion at a position where the shaft of the transfer roller can be inserted and attached when the transfer roller is attached to the frame.
A sheet transfer device characterized by. Further having a bearing, which rotatably supports the transport roller,
The transport roller is supported by the frame via the bearing.
When the transport roller is moved in the axial direction in order to remove the transport roller from the frame, the side end portion of the gear comes into contact with the contact portion and the axial movement of the gear is restricted. , The shaft of the transport roller is disengaged from the gear,
The sheet transfer device according to claim 1, wherein the transfer roller and the bearing can be removed from the frame. Further, the transport roller has a restricting member that restricts the movement of the transport roller in the axial direction with respect to the frame in a state where the transport roller is attached to the frame and transports the sheet.
The sheet transfer device according to claim 1 or 2, wherein when the transfer roller is removed from the frame, the restricting member is removed from the shaft of the transfer roller. A drive transmission means for transmitting drive to the gear and
A belt pulley means having a belt and a pulley that rotate integrally with the gear is provided.
The transfer roller has an upstream transfer roller and a downstream transfer roller arranged on the frame at intervals in the sheet transfer direction.
The upstream transport roller is characterized in that the gear is rotated by the drive transmission means, and the downstream transfer roller is rotated by transmitting drive to the belt pulley means by rotating the gear. Item 3. The sheet transfer device according to any one of Items 1 to 3. The image according to any one of claims 1 to 4 is an image characterized in that it is configured to be able to be drawn out from an image forming unit that forms an image on a sheet conveyed by the sheet conveying device. Forming device. The sheet transporting apparatus according to any one of claims 1 to 5.
An image forming apparatus having an image forming unit for forming an image on a sheet conveyed by the sheet conveying apparatus.

Images